Staphylococcal Infections Penicillin has proved to be the most effective chemotherapeutic agent yet discovered for the treatment of staphylococcal infections.55,56,62 The usual mortality rate of 80 per cent in untreated cases of staphylococcic bacteremia63 has been reduced with penicillin treatment to 20 per cent or even less. Doses between 150,000 and 300,000 units a day are usually desirable until the infection has been controlled. The daily dosage may then be reduced to 120,000 units. It has been widely recognized that in severe staphylococcal infections striking improvement may not be observed for several days after the beginning of treatment. It is . . .